First of all - welcome!
If correctly wired, your outlet should be the same as a modern range. ie 2 hots, a neutral and a ground.You see 220V across the 2 hots but 110V from each hot to neutral. Most equipment in your RV will use one or other of the 110V circuits.
I assume everything has been working OK so it sounds to me as if you have lost your neutral and are getting way more than 110V on one half of the rig and way less on the other.
You may have done damage to the equipment that saw the "high" side.
A voltmeter is in order before you try to run anything.
Check the supply outlet and in your panel in the unit.
Keith J.
Sold the fiver and looking for a DP, but not in any hurry right now.